Abstract: The poor rock stability and high ground pressure in the western zone of the Chambishi Copper Mine in Zambia resulted in serious roof failure of the along strike drifts. The reasons of roof failure and the following changes in the surface stress of drifts were analyzed under the conditions of gently sloping layered surrounding rock. Furthermore, a conclusion was drawn that the drift section after roof failure tends to be stable, because it becomes self-adaptive to rock mass structure and pressure since then. Therefore, an erect triangular cross-section of the drift is proposed instead of the existing 1/4 tri-center arch section, with rock bolts used to stabilize the rock structure. After the implementation of the scheme, the stability conditions of drifts were significantly improved and the utilization ratio of drifts was increased from 90% to 100%, i.e., a remarkable success.